This application claims the priority of German Application No. 199 06 970.0 filed Feb. 19, 1999, which is incorporated herein by reference.
This invention relates to a reconnaissance sonde which may be released as a payload from a carrier projectile in an area to be monitored, for example, a battlefield. The reconnaissance sonde, after settling on the ground, wirelessly transmits reconnaissance information to a data processing apparatus.
Reconnaissance sondes of the above-outlined type are known, for example, from German Patent No. 30 13 405. For determining target-relevant information, the known sondes have, for example, acoustic, optical, magnetic and/or radar sensors. The information detected by the sensors is wirelessly transmitted to an evaluating device associated with a fire control computer of a weapon system and the information is converted to flight path correcting values for a target-combating projectile. The German patent, however, offers no description concerning the actual structure of the reconnaissance sonde.
German Offenlegungsschrift (application published without examination) No. 41 04 800 also discloses a reconnaissance sonde which may be released as a payload from a carrier projectile in the zone of a battlefield. The sonde disclosed therein transmits target-relevant information as it descends and rotates, suspended from a parachute.
It is a disadvantage of such a reconnaissance sonde, among others, that a reconnaissance of the battlefield is feasible only during a relatively short period.
It is an object of the invention to provide an improved reconnaissance sonde of the above-outlined type which has a relatively compact construction and with which very accurate target determination is feasible during a continuous monitoring of a battlefield.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the reconnaissance sonde includes a housing having top and bottom portions; a parachute disposed at the top housing portion; a plurality of support legs peripherally mounted on the bottom housing portion in a circumferential array and having a folded state and a deployed state; a drive for simultaneously moving the support legs from the folded state into the deployed state upon landing of the sonde; a GPS navigation system, a magnetic field sensor and an attitude sensor for accurately determining a position and an attitude of the sonde; at least three target bearing determining sensors supported by the housing and distributed circumferentially; an electronic evaluating apparatus supported by the housing and connected to the GPS navigation system, the magnetic field sensor, the attitude sensor and the target bearing determining sensors for evaluating measured sensor signals thereof; a transmitting and receiving apparatus connected to the electronic evaluating apparatus for wirelessly transmitting evaluated signals to a remote data processing apparatus or an additional sonde; and a battery for supplying electric energy to the sonde components.
It is a basic principle of the invention to provide the reconnaissance sonde with a GPS navigation system (Global Positioning System) and with at least one magnetic field sensor for orienting the sonde relative to the magnetic north pole, so that after the sonde lands on the ground, a very accurate attitude and position determination of the sonde itself and the (absolute) target-relevant information determined by the sonde may be obtained.
Advantageously an air bag is used for deploying the supporting legs of the reconnaissance sonde to ensure its uniform and rapid upright positioning immediately after it contacts the ground. The air bag, in its inflated state, has a circular shape relative to the longitudinal axis of the sonde housing and thus deploys all the supporting legs simultaneously.
Conventionally acoustic sensors (microphones) may be used for determining the bearing of a target as well as the target classification. Their measuring accuracy is increased by suitable measurements performed by seismic sensors (geophones). It is further feasible to determine the target bearing with the aid of a radar sensor and to perform the target classification by using an IR camera.